Retinal Photoreceptors and Microvascular Changes in Prediabetes Measured with Adaptive Optics (rtx1™): A Case-Control Study

Abstract

Background Patients with prediabetes are at risk for diabetes, cardiovascular events, and microvascular complications. The rtx1 (Imagine Eyes, France) permits early detection of changes in the retinal photoreceptors and vessels. Objective Cone parameters and retinal microvasculature were analyzed with the rtx1 in 12 prediabetic patients and 22 healthy subjects. The analysis was based on cone density (DM), interphotoreceptor distance (SM), cone packing regularity, and retinal vessel parameters: wall thickness, lumen diameter (LD), wall-to-lumen ratio (WLR), and cross-sectional area of the vascular wall. Results DM in the prediabetic group was not significantly lower than that in the control group (18,935 ± 1713 cells/mm2 and 19,900 ± 2375 cells/mm2, respectively; p = 0.0928). The LD and WLR means differed significantly between the prediabetic and the control groups (LD 94.3 ± 10.9 versus 101.2 ± 15, p = 0.022; WLR 0.29 ± 0.05 versus 0.22 ± 0.03, p < 0.05). A multivariate regression analysis showed that the WLR was significantly correlated with BMI and total cholesterol. Conclusions Abnormalities found in rtx1 examinations indicated early signs of arteriolar dysfunction, prior to impaired glucose tolerance progressing to diabetes. The rtx1 retinal image analysis offers noninvasive measurement of early changes in the vasculature that routine clinical examination cannot detect.

Adaptive Optics (rtx1) High-Resolution Imaging of Photoreceptors and Retinal Arteries in Patients with Diabetic Retinopathy

“…Recently published studies of prediabetic patients or patients with diabetes but without signs of DR showed no differences in cone density and mosaic, however [22, 28]. Our findings from a previous study indicated that cone density was not affected by impaired glucose tolerance [22].…”

“…Photography taken from the eyes with severe DR shows a full spectrum of microvascular abnormalities [3, 4, 7]. Recently, advances in high-resolution imaging techniques, such as AO and optical coherence tomography angiography (OCTA), have expanded our ability to visualize the living human retinal vasculature noninvasively [11–14, 19, 22].…”

Adaptive optics imaging of the human retina

“…While diabetes has often been considered to primarily affect the inner retina, there is growing evidence that the outer retina is also majorly involved in diabetic eye disease (Du et al, 2013; Elsner et al, 1987; Kern and Berkowitz, 2015; Lammer et al, 2016; Lombardo et al, 2014a; Sawides et al, 2017b; Scarinci et al, 2016; Soliman et al, 2016; Tan et al, 2015; Zaleska-Zmijewska et al, 2017). This is seen as either decreases in cone numbers (Lombardo et al, 2014a; Soliman et al, 2016), or as increased irregularity of cones (Lammer et al, 2016; Nesper et al, 2017) in eyes with diabetes.…”

Consumption of a high fat diet promotes protein O-GlcNAcylation in mouse retina via NR4A1-dependent GFAT2 expression

“…However, neuro-retinal deficits can clearly precede and even predict the visible signs of microvascular disease in diabetic patients [reviewed in (48)]. Importantly, clinical studies by multiple investigators have reported retinal defects (49,50) and impaired visual function in pre-diabetic humans with impaired glucose tolerance (51,52). Thus, there is an urgent need for interventions that target the initiating biochemical changes that contribute to the early non-proliferative stages of disease progression.…”